A set of rules that govern how something works.
Within a computer science:
- A communication protocol is a system of digital rules for data exchange within or between computers
- When data is exchanged through a computer network, the rules system is called a network protocol
Logical Protocol (SMTP) - It is how emails are sent
- HTTPS - Browsing through the net
Lowest layer is logical and the highest is physical.
Physical layer = Describes electrical and physical specifications for devices: Cable, connectors, hubs.
Data link layer = Provides connections between hosts on the same network: Ethernet
Network layer = Provides connection between hosts on different networks :IPv4 and IPv6. Routing of packets.
Transport = Provides transport of data: TCP and UDP. End to end connections.
Session = establishing a connection. Controls the dialogs between computers (handshake). Also controls duplexing termination and restarts.
Presentation = compressing the data. Provides a context for communication between layers
ASCII Characters, Encryption and decryption. Compression.
Application = HTTPS, where we find network application eg mail, browser
It hands communication between computers across networks.